As a sealed medical storage for an intravenous dripping or dialysis et al., a multi-liquid mixing type such as double liquid type has been proposed. In such a sealed medical storage of double liquid mixing type, the medical bag is formed from flexible material films and is provided with a weak seal portion, which divides or separates the space inside the medical bag into compartments for storing therein with different medical liquids. At the outer periphery of the medical bag, an outlet port for medical liquid as a thermoplastic mold product is provided, which outlet port forms as a tubular shape having an inner space, which has a first end opened to one of the compartments and a second end provided with a rubber plug. Prior to the administration of medicine to patient, the medical bag is pressed from its outside, so that the weak sealed portion is separated, so that a single chamber is created in the medical bag, causing the medical liquids to be mixed with each other. Then, a needle of an infusion set is pierced to the rubber plug, which allows the mixed medical liquids to be administered.
It sometimes is needed that additional medicines, such as vitamins or antibiotics, should be blended or mixed to the infusion liquid in a sealed medical storage. As a means for an addition of an additional medicine, a construction has been proposed, wherein an inlet port for the additional medicine is provided at a portion of the outer periphery of the medical bag opposite to the outlet port. The inlet port has a normally closed leading end, which extends into the space inside the medical bag and is opened by its breakage. Under the closed condition of the inlet port, the additional medicines are held in the space inside the inlet port. When an infusion operation is commenced, the leading end of the inlet port is broken by a manual operation from the outside of the medical bag in a manner that the inlet port is opened to the space inside the medical bag, which allows the additional medicines to be mixed with the infusion liquid. See Patent Publication No. 1.
A construction has also been proposed, wherein an inlet port for additional medicine formed as soft small bag is arranged in a medical bag and a pointed seal portion is provided for integrating the inner bag with the outer bag. A widening of the medical bag upon its separation causes the pointed seal portion to be broken, which allows the additional medicine such as vitamin to be blended.    Patent Publication No. 1: Japanese Un-Examined Patent Publication No. 2003-159309